max quench ?

[waypastcrazy]

Ok engine guys I am trying to get max quench on my 429 I think I need the piston 0 on the deck or 005 down in the hole maybe 005 out the top not sure because of rpm stretch on rod and piston I plan on turning 6 to 6500 rpm with je pistons and scat h beam rods which are supposed be good for 950 hp and stock crank with felpro head gaskets. I do not know how much stretch to allow for with these rods and pistons but I want max quench so it will have a good ignition or I should say no ignition in that area which will also help on detonation by making things cooler in there and proper extiguishing of flame front.I do know every 10thou close to flat of the head is worth 7 or 8 lb ft of torque and I need all I can get!any and all advice will be greatly appreciated thx in advance robert

[waypastcrazy]

Had to edit reread realized could have been confusing sorry

[coupe]

Hmm. Still confusing. :poke: :D
Sounds like a question for David Vizard.

First, I wouldn't worry too much about the rod stretch. The H-beams are 4340 and the JE's are not known for being a portly piston, so you're good there. And the 6k RPM is not in the stratosphere either.

Now, I believe what you're after is an efficient burn that is not prone to detonation. Hopefully, your heads have been designed with an efficient chamber and you're not going overboard on the compression ratio. The chambers go hand in hand with the piston crown design. Together (along with the cam of course), they will determine the air/fuel distribution for the burn; alot of power can be had by making these components work well together. I'm not so sure theory will get you what you're after...but after running it, the combustion will leave a footprint on the piston by which to see where things are rich and where they are lean.

[SlowJoe]

way to many big words in there for me!!!!!!!

[waypastcrazy]

Thx coupe!maybe I should have asked how much will these parts flex at my rpm range I can figure the rest from there.I have not run these brands before.just want a tight quench and not have the piston kiss the head at peak rpm.as for compression I will be aprox 9.25 what I am after is the closer the piston is at the top it will extiguish the flame and create a cooler cylinder less prone to detonation

[waypastcrazy]

That's why its called quench it puts out fire before the fire is needed.lol got a laugh out of it anyway.just trying to make some free power.its not cheap these days

[coupe]

..just trying to make some free power.its not cheap these days I wouldn't worry too much with 429 cubic inches on tap. Headers, carb, and a cam ought to get you over 500hp with ease.

[Craig K.]

Usually you should go for 0 top of piston to deck, this in a normal applicantion is ideal, if you want a little more, then your right you want the piston slightly over flush to the deck.

As stated by coupe, those rods/pistons should not stretch at that RPM level.
I ran a 0 deck with stock 302 rods to 6500 with no problems (I know totally different application).
Also make sure you have a good spring on the valves, make sure you get them out of the way.

[LeeH]

The target for a steel rod is .032-.036 quench, More than that and you run into detonation issues and less can cause clearance issues on missed shifts.